The costs for building new structures has rapidly increased and builders and developers are constantly searching for manners in which to minimize construction costs to create affordable buildings. As a result, one principal goal of both housing providers and potential housing purchasers is to reduce costs. Major elements that make up the costs of construction include both the materials used for the structure and labor that is involved in the construction process. In connection with the materials, conventional construction techniques typically use relatively expensive materials such as wood and steel. Further, the labor necessary in the construction process requires a relatively skilled labor force that adds to the expense. Conventional construction techniques require that building materials that are used must be worked on site to conform to the building plans. It is generally recognized that if the time in which to construct the structure can be reduced, the labor costs may be commensurately be reduced.
While selecting less expensive materials can reduce the overall construction costs, the resulting structure may be of poor quality and the resulting structure often will not last. Dwellings that are constructed of low cost materials may not be attractive, and as a consequence, are difficult to resell. In some applications—such as the provision of temporary housing—the durability and resale value is not a significant concern. However, when units are used for permanent housing, the durability and ability to resell the structure often influences the choices for materials.
In many circumstances the need or demand for housing can be manifested very quickly. For example, in circumstances after natural disasters, such as hurricanes, tornadoes, forest fires, earthquakes, mud slides and volcanic eruptions, large populations may be displaced and rendered homeless. Political turmoil may also result in the movement of numerous refugees that require housing. Military forces also have acute and rapid requirements for housing on short notice, such as when there is a rapid need to deploy or train troops.
When natural disasters such as tornadoes, floods or hurricanes strike a community, homes often are destroyed and there is an immediate need for housing. In the past, trailer homes have been transported to the natural disaster site to provide refuge for the people left homeless and to provide living and work space for relief workers. Because trailer homes are relatively large, the transportation of the house trailers to the natural disaster site presents problems. Often the trailers are too large for roadways, too heavy for bridges and airlifting trailers is costly. Further, the movement of trailers over long distances is expensive in terms of fuel costs, trucking costs and labor expenses. Because the trailers must be engineered to be transported, costs are further increased. Pre-manufactured housing such as trailers or mobile homes can provide a number of advantages but often the costs involved make this alternative prohibitive or unattractive. Because the structure is pre-manufactured, there is little flexibility for alternative floor designs. Because the structure must be transported, the dimensions that the structure can be built are limited in terms of width, height and length.
Another conventional response to acute housing needs is to provide tents. Tents are relatively inexpensive, can be quickly erected, and are easy to transport. However, tents cannot be secured to the degree of a building that has rigid walls, they are typically not well insulated and therefore are not suitable for cold weather applications. Most tents do not have advantages of glass windows and they are also not particularly durable. It is self evident that tents are limited to single story structures. As a result, tents are generally not considered suitable for long term housing solutions.
In response to the need for alternative structures, there has been considerable development of prefabricated or modular shelter structures. Most of the prefabricated shelter structures that are disclosed in the prior art require special fasteners and hardware in order to produce a shelter with desired rigidity and ruggedness. Often, the use of the special hardware requires additional training and a skilled workforce to assemble the structures on site. If special hardware is lost, the replacement of the parts necessary to assemble the materials may be difficult. Some of the building structures and shelters that have been disclosed in the prior art have panels that are connected by conventional fasteners, such as bolts, spikes, nails, rivets, or pins. Typical of such structures are the buildings shown in U.S. Pat. No. 1,924,414; U.S. Pat. No. 3,512,316; U.S. Pat. No. 3,566,554; U.S. Pat. No. 3,838,545; U.S. Pat. Nos. 3,992,829; 4,637,179; and U.S. Pat. No. 5,285,604. However, in view of the numerous attachment points between building panels, these buildings are difficult and time-consuming to both assemble and disassemble.
U.S. Pat. No. 4,726,155. (the '155 patent) discloses the use of hinged panels connected to one another that avoids some of the problems with connecting adjacent panels. The structure disclosed in the '155 patent can be rapidly assembled on site but still requires significant assembly time at the production facility. U.S. Pat. No. 3,802,134 discloses the use of numerous latch members to interlock adjacent panels thereby simplifying the assembly process on site. Another approach disclosed in the prior art is the use of interlocking tongue-in-groove arrangements to connect adjacent panels.
Sometimes modular elements used to construct a dwelling are separately shipped to the location. However, often the size and weight of the modular components is a significant concern, especially when the transportation requires airlifting or overland truck routes. Some of the pre-engineered components have dimensions that make transportation and subsequent subassembly on the building site difficult. For example, pre-manufactured roof trusses often require a crane or many laborers to position the roof truss on the top of a building.
Efforts to try to reduce and simplify the labor involved with conventional construction techniques have been significant. For example, ceiling trusses and floor joists are sometimes pre-manufactured and delivered to the job site and this technology has served to reduce both material and labor costs. The development of power nail guns has significantly reduced the time spent in connecting the structural parts of a building. Still, conventional stick frame housing cannot be quickly assembled and this building technique generally requires significant skilled carpenter labor, as well as other tradesmen. There is still required significant on site cutting and assembly of raw lumber in connection with conventional construction. Conventional construction techniques also generate significant waste.
The applicant and inventor developed a system to address many of these issues that was disclosed in Automated Builder, August 1996. The present invention is directed to further improvements to the system that was previously disclosed. In this regard, the assembly of the panels described in the applicant's prior art system required significant efforts. The prior art panels are comprised of expanded polystyrene blocks and opposite cementitious skins. Cement was set within the frame—a continuous welded part—to set. The foam blocks were assembled on top of the first layer of cement. Further, the prior art system did not have a solution to construct corners, to attach adjacent panels, or to provide panels for floors.
There is a continuing need for improved, inexpensive, durable, pre-manufactured materials that can be quickly assembled into structures. There also continues to be a need to provide economical building systems which can be rapidly constructed with a minimum of labor skills. Ideally units constructed should be able to be secured, have low maintenance requirements, and be energy efficient. The building system should also accommodate different designs and floor plans that can be catered to the particular application. Ideally, the system should include all of the required structural components including floors, walls, ceilings, trusses, and roof elements. Moreover, the system should be adaptable to accommodate locally available materials that are abundant and make economic sense to substitute for the structural component based upon local conditions. Further, the materials and the building system should be able to be adapted to build different types of buildings. Such a system should be able to be assembled with minimal training or skills and with conventional tools. More particularly, the system should be capable of eliminating the need to use a wide assortment of conventional materials that are expensive and their use involves considerable labor and skill, such as structural graded lumber, steel parts such as I beams and joist hangers, seismic plywood panels, plastic non-biodegradable and adhesive products.
Accordingly it is an object of the present invention is to provide a modular construction system using panels that can be assembled into structures.
A further object of the invention is to provide a method of manufacturing panels that can be assembled into structures.
It is yet a further object of the invention to provide structures with low maintenance requirements, provide for the conservative use of natural resources, and provide flexibility in style and design.
A further object of the invention is to provide a modular building panel that has integrated insulation.
Another object is to provide a total integrated system of structural components that functions as a building system of floors, walls, ceilings and trusses that can replace other materials that are conventionally used in wood frame or masonry buildings.